iOS: Castro is one our favourite podcast managers on iOS because it's easy to use, has a few clever management options, and works great for people who only listen to a few podcasts. Today, the apps gone free while adding in a bunch of new iOS 9 features.
Feature wise, the additions include Spotlight search, an in-app browser, and a number of 3D Touch features. Beyond that, the app still has the gesture-based interface that makes it easy to use on the go, and a ton of storage management options that make it great for people with 16GB iPhones. The apps also now free with an optional patronage if you want to tip the developer.
Castro (Free) [iTunes App Store]